In the recent automotive industry, as the interest in environment and energy is increased around the world, research into improvement in fuel efficiency has been conducted and a research and development to implement weight reduction, miniaturization, and multi-functional performance to meet various consumer needs has been continuously conducted. In particular, a research and development for a hybrid vehicle simultaneously using power and electric energy tends to be increased.
The hybrid vehicle has mainly adopted an idle stop/go system which automatically stops an engine at the time of stopping, such as waiting for signal, and restarts the engine by operating a transmission again. However, even in the case of the hybrid vehicle, since an air conditioner is operated by the engine, when the engine stops, a compressor also stops, such that a temperature of an evaporator rises and thus comfortableness of a user deteriorates. Further, since a refrigerant inside the evaporator is easily evaporated even in a room temperature, the refrigerant is evaporated for a short period of time in which the compressor is not operated. Therefore, even though the engine is operated again to operate the compressor and the evaporator, there is a need to compress and liquefy the evaporated refrigerant, such that it takes much time to supply a cold wind to the interior of a room and the entire energy consumption may be increased.
Meanwhile, Japanese Patent Laid-Open Publication No. 2000-205777 (Title of the Invention: Heat Storage Heat Exchanger) has been proposed to increase cooling efficiency, which is illustrated in FIG. 1.
As illustrated in FIG. 1, the heat storage heat exchanger is characterized in that a heat exchange medium passage 191e through which a heat exchange medium is distributed and heat storage material chambers 191f and 191f′ in which a heat storage material is stored are integrally formed by a tube 191 having a double pipe structure and an outside of the tube 191 having a double pipe structure is provided with a passage 194 through which a fluid heat-exchanged with the heat exchange medium is formed.
However, as illustrated in FIG. 1, the heat storage heat exchanger includes the tube formed by bonding several boards to each other, such that the bonding defect may frequently occur, is formed to have the double pipe structure, such that it is difficult to be manufactured, and has a problem in that the heat exchange medium therein is mixed with the heat storage material when the bonding defect occurs. Further, even though the bonding defect occurs, it is difficult to find out the bonding defect portion.
Further, the heat storage heat exchanger has a problem in that since the inside of the double pipe is provided with a passage through which the heat exchange medium moves and the outside thereof is provided with the heat reserving material chamber in which the heat reserving material is formed, the heat storage material easily stores the cold air of the heat exchange medium therein but air passing through the outside of the double pipe structure contacts the heat reserving material chamber to reduce a heat transfer of the heat exchange medium. Further, a fin inserted into the outside of the double pipe tube also contacts the heat storage material chamber but is not directly connected to the heat exchange medium passage, thereby reducing the heat exchange efficiency.
To solve the above-mentioned problem, the present applicant has proposed Korean Patent Laid-Open Publication No. 2007-0111390 (Title of the Invention: Cold Reserving Part Equipped Evaporator), which is illustrated in FIG. 2.
In Korean Patent Laid-Open Publication No. 2007-0111390 illustrated in FIG. 2, a tube 30 formed by bonding a pair of plates 10 having left and right sides each provided with refrigerant passages 11a and 11b is used and a cold reserving part 20 in which a cold reserving material is stored is formed between the refrigerant passages 11a and 11b of the tube 30.
Meanwhile, the heat exchanger equipped with a cold reserving part has a problem in that as the refrigerant and the cold reserving material each move, a component to charge a cold reserving material is required along with a pipe for providing the introduction and discharging of a refrigerant and when a component for charging the cold reserving material protrudes to the outside, it is difficult to prevent miniaturization and a space in which the refrigerant moves or a storage space in which the cold reserving material is stored is reduced so much.
Further, since condensed water may be formed on an outer surface of the heat exchanger for air conditioning, the heat exchanger easily discharges the condensed water by coating a coating solution on the outer surface thereof, suppresses a smell from occurring, and suppresses inhabitation of mold, and the like.
Generally, the coating processing dips the heat exchanger in a coating solution and dries the coating solution to form a coating layer and the coating solution introduced into the heat exchanger may corrode the heat exchanger and thus reduce the overall durability of the heat exchanger.
However, the heat exchanger equipped with a cold reserving part has a problem in that it is highly likely to introduce the coating solution into the heat exchanger through a part to charge the cold reserving material and thus a separate process to seal the part to charge the cold reserving material is required.
In addition, the heat exchanger equipped with a cold reserving part according to the related art illustrated in FIG. 1 has the double pipe form and when the coating solution is introduced into the heat exchanger, hardly removes the coating solution, such that the occurrence frequency of defects may be increased due to the introduction of the coating solution, thereby causing the reduction in productivity.
Therefore, a need exists for a heat exchanger to be able to expect the rapid and high cold reserving performance, prevent corrosion due to the coating solution, and increase the durability and manufacturing performance.
Patent Document 1) Japanese Patent Laid-Open Publication No. 2000-205777 (Title of the Invention: Heat Storage Heat Exchanger)
Patent Document 2) Korean Patent Laid-Open Publication No. 2007-0111390 (Title of the Invention: Cold Reserving Part Equipped Evaporator)